Re: CNC Engraving

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Cletus Berkeley"
<cberkeley@y...> wrote:

>
>
> Hi Folks,
> I need help from someone familiar with Corel 10 and
> CNC Engraving. When I export an HPGL Corel file to the
> machine, the characters engrave as an outline and generally I desire
> this. But, how can I get to engrave the characters as filled?
> Would appreciate any help with this. Using Master5.
> Cheers, Cletus

HPGL is plotter language. The concept is a machine with a pen
tracing stuff in XY. As such doing "fills" is not that easy. You
have an option in the HPGL export in Corel to "use lines for fills"
(or something close to that). I have never engraved using fills
which sorta is not engraving anymore but milling. What kind of bit
are you using? The typical v shaped engraving bit is not going to do
well cutting smooth bottom fills. If you just want the illusion of
fills the parallel lines might work. If you want a smooth bottom
(regardless of the depth) you need a flat bottom cutter and you need
to generate the g-code using a CAM package. One low cost option is
to go ahead and export the file as HPGL and bring it into SheetCAM
(www.sheetcam.com) and use different tools to cut on-line or to do
the depth cut using a small end mill. If the letters are small you
will have a problem finding an end mill small enough to make it into
the tight corners. Check out the old engravings in the 17 and 18th
century. They cut lots of tiny lines to simulate shading.

One last thing is that you could do your own line fills in Corel or a
pattern of lines (crosshatch) and fill the sections prior to export.
HPGL is okay with lines, curves and open or closed vector objects but
it doesn't do a solid fill. That's the nice thing about a CAM
package is you can select a closed vector object of any shape and
define the toolpath and tool type to cut any depth you want.



What engraving software and machine control are you using?